Question

se x+y =10 e x-y = 9 então qual o valor (x+y)x( x-y)

Answer 1

x+y=10
x-y=9
2x=19
x=9,5

9,5+ y=10
y=10-9,5
y=0,5
(x+y)x (x-y)
10.9,5 (9,5-10)
10.90,25-4,75
10.85,5
855 é a resposta.

Answer 2

x+y=10
x-y=9

x=9+y
x= 9+1/2
x= 19/2

9+y+y=10
2y=10-9
2y=1
y= 1/2

(x+y).(x-y)
(19/2+1/2).(1/2-19/2)
(20/2).(18/2)
10.6= 60